The flour is used principally by bakers for adding to rye and wheat flour in making bread. The proportion for wheat bread is 5 to 10 per cent. of the ground potato flour, and for rye bread the amount can be increased to 15 per cent. It is claimed that the addition of the ground potato flour to the rye or wheat flour gives the bread a good flavor, makes it more digestible, and keeps it fresh for a comparatively long time. It is also used to a slight extent in thickening soups and sauces "There are no statistics available that would indicate the annual consumption of ground potato flour in Germany, but as an industry the manufacture of the flour has not attained large proportions. It is sold principally to bakers. It is known to the trade as 'Walzmehl,' 'Kartoffel Walzmehl,' 'Patent Walzmehl,' and 'Fiddi-chower Walzmehl.' The prices vary according to the potato crop and the quality, and range from $4.76 to $7.14 per 100 kilos (220.46 pounds).

During the last sixty years potato farming has assumed large proportions in the Netherlands, due in great measure to the development of the potato-flour industry. In 1860 the total potato area was 273,318 acres, while in 1908 there were 395,089 acres. The following table shows the production by provinces in 1908 and the area of land devoted to the industry:

Provinces

Production

Area

Percentage of tillable area

Bushels

Acres

Drenthe................

13,567,634

40,515

34.7

Friesland ..................

12,459,213

40,192

38.1

Gelderland ...................

11,729,464

65,609

22.6 .

Groningen ..................

18,565,776

48,815

15.1

Limburg...............

4,960,600

30,562

13.7

North Brabant ,,,,,,,,,,,,,,,,

9,634,745

55,784

15.2

North Holland.........

2,456,606

11,209

11.4

Overyssel.............

. 9,959,664

40,031

34.7

South Holland ...........

. 6,294,550

26,497

18.0

Utrecht...............

. 1,076,857

7,853

19.7

Zeeland...............

6,093,868

28,022

11.3

Total.............

. 96,798,977

395,089

Seventy-four per cent. of the potato crop is used for food and seed and the remainder supplies the raw material for manufacturing purposes. Three fourths of the manufacturing is done in the province of Groningen, and the remainder is confined to three other provinces. Of the 48,815 acres of potatoes in Groningen, over 37,000 were planted for industrial purposes.

The scientific fertilization of the soil has become a very important feature of the potato industry in Groningen. Sometimes $32 to $50 worth of fertilizer is scattered on one hectare (2.471 acres) of ground. The land is valued at fully $500 per acre and rents at $22.50 per acre per year. The fertilizers consist of about 200 kilos of Chile saltpetre and 700 kilos of superphosphates to the hectare. Potatoes raised on this highly fertilized soil are not very edible, being cultivated principally for their industrial properties. There is a sentiment in favor of using the factory waste for fertilizing, but it has not proved a success as yet.

The methods of planting, cultivating, and harvesting potatoes have not advanced as they should. Several picking machines have been tried of late, but not to the satisfaction of the planters. They want a machine that will not only dig the potatoes out of the ground, but clean off the dirt and empty them into a sack as well. A potato digger that merely uproots the potatoes, leaving them scattered over the ground to be picked up and sacked by hand, saves little labor, as they still have to be cleaned, sacked, and often shaken loose from the roots and vines.

In the cooperative potato producing and manufacturing enterprises the packing is usually let to contractors at from $0.09 to $0.10 per row of 140 meters (459 feet). That includes stacking them in piles and covering them with straw. The laborers are also given free potatoes during the picking season. Sometimes these contractors are the heads of large families, but there are also contractors who sublet to individual workmen. They usually pay the pickers $0.06 per row. One person is able to pick seven of these rows per day of seven hours. The whole family usually joins in the work, camping out on the potato field during the season. Independent farmers often pick their own crops.

A great impetus to the potato-flour industry was given by the cooperative method introduced during the last two decades. In fact the introduction of that system has really joined the opera-. tion of producing raw materials and manufacturing them into potato flour. It led to the establishment of cooperative experiment stations whose object it is to study the scientific culture and treatment of potatoes for industrial purposes in all practical phases of the industry. Previously there was no organization between planter and manufacturer, which frequently proved disastrous to both.

The first step toward organization was taken in 1890 by several of the large manufacturers, but arrangements were not completed until 1900, owing to the lateness of some in joining. The factories then announced uniform prices for raw potatoes and the farmers had to sell on their terms. The latter retaliated by organizing cooperative producing societies, which soon developed into manufacturing institutions as well. There are therefore two systems of operating, one in which the farmers cooperate to the extent of owning shares in the factory and the other in which the trading is independent and speculative.

The different cooperative plants are of course still competitive in respect to each other. They have their own trademarks, they sell independently through domestic and foreign agents, and are keen rivals in the production of superior qualities. Of the thirty-four potato-flour factories in the Veenkolonien, eleven are cooperative. The largest independent factory has a capital of $600,000 and the buildings and machinery are valued at $100,000. This factory has small branches in various sections of Groningen. Some of these mills have a capacity for grinding over 28,000 bushels in twenty-four hours; the smallest, about one fourth of that amount. Three fifths of the total production of potato flour of the country is ground in independent mills. The demand for Dutch potato flour is always greater than the supply.

The season for manufacturing potato flour is usually about ten weeks in duration - from the middle of September to the last of November. The fine waterway system of Groningen greatly expedites the delivery of potatoes, naturally shortening the season, and in fact accelerating the industry. The great network of canals and other waterways makes it possible to transport the potatoes directly from the field to the factory, the latter always being on canals that accommodate forty to 100 ton vessels. Potatoes are sent in shiploads of 2,000 to 3,000 bushels each. Frequently these ships are owned by the factories, though sometimes by private individuals or transportation companies.